The present invention relates to a toner loading cartridge for replenishing toner in automatic reproducing machines. In particular, the present invention relates to a toner loading cartridge which can be used in a "White Glove" operation to replenish depleted toner in a toner dispenser. By the present invention, it is possible to replenish toner in automatic copying machines without contaminating either the interior or exterior of the machine, or the operator with loose toner powder.
In electrostatographic reproducing apparatus commonly in use today, a photoconductive insulating member is typically charged to uniform potential and thereafter exposed to a light image of an original document to be reproduced. The exposure discharges the photoconductive insulating surface in exposed background areas and creates an electrostatic latent image on the member which corresponds to the image areas contained within the usual document. Subsequently the electrostatic latent image on the photoconductive insulating layer is made visible by developing the latent image with developing powder referred to in the art as toner. Most development systems employ development material which comprises both charged carrier particles and charged toner particles which triboelectrically adhere to the carrier particles. During development, the toner particles are attracted from the carrier particles by the charged pattern of the image areas on the photoconductive insulating area to form a powder image on the photoconductor. This may subsequently be transferred to a support such as copy paper to which it may be permanently affixed by heating or by the application of pressure.
In the commercial electrostatographic machines available on the market today, the supply of toner in the developer mix must be periodically replenished to maintain copy quality. Typically this is through the use of a dispenser of the toner which contains a supply of toner. Periodically however, this supply of fresh toner in the toner dispenser must also be replenished. Initially this was accomplished merely by pouring loose toner from a toner container into the toner dispenser. This is a very untidy operation with toner being spilled on the interior and exterior of the machine as well as on the machine operator which can result in soiled and/or damaged clothing.
The loose toner is very light and fluffy and is carried by the smallest air current to all parts of the machine. Externally of the machine in addition to protential soiling of the operator personally and his/her clothing, the toner can collect on machine covers, stands, carpets, walls, and furniture surfaces.
The toner which is loose within the machine creates even more serious problems. The air currents take the toner and spread it throughout the entire machine. The toner can contaminate any charging corotrons resulting in non-uniform charging and therefore non-uniform formation of developed images. In addition, loose toner within the machine may contaminate sheet feed rolls particularly in the copy sheet feeder leading to skewed sheet feeding, paper jams, and machine shut down. In addition, toner floating in the air within the machine may deposit on the copy sheet before it enters the fuser and show up on the final copy as very small, fused black spots thereby substantially increasing background and reducing overall copy quality.
Altogether toner contamination from the above causes as well as others is a major cause of machine shut down and thereby a service call by a skilled technician to correct the problem. However, once the loose toner gets into the machine, it is very difficult, if not impossible, at times to clean the copier. The best method so far developed has been with the use of a vacuum cleaner which the service technician has to carry for such a purpose.
There has therefore been a long desire for a clean dry process to replenish toner without creating the above noted problems. There has been a long desire to provide a toner cartridge which can replenish toner in the copying machine without contaminating the interior and exterior of the machine or the machine operator. A number of approaches have been tried most of which require that the toner replenishing cartridge be left in the machine during machine usage. This approach has typically suffered from the fact that a gap between the toner reservoir and the cartridge do is indeed exist and toner will then escape into the machine.